In many mobile and/or battery-operated electronic devices, the total amount of power consumed by the device is a significant consideration. Many such electronic devices require significant power conservation in the system. Some such electronic devices also include the transferring of data signals within the device along parallel lines of a data bus. For example, a memory or DRAM may be included in the electronic device, and such memory can have a data bus with long parallel lines that transfer data signals within the memory.
In general, a bus used to route significant amounts of data between various parts of the system includes a plurality of parallel and relatively long metal lines or conductors that use switching power in the transmission of data. Each of the metal lines of the data bus may be subject to capacitive coupling from neighboring lines. For example, if a voltage on one of the metal lines is reduced from a logic high voltage to a logic low voltage, a logic high voltage on adjacent lines may also be reduced due to capacitive coupling between the lines. Furthermore, there is a general capacitive load associated with the data bus. For example, a capacitive load can be associated with connecting transistors or due to coupling with signal or power lines above and below a particular line.
As the physical dimensions of a data bus are reduced, and the metal lines are spaced closer together, switching power due to the effect of capacitive coupling and capacitive loading is increased. For many semiconductor devices that are components of systems with such data buses, a significant amount of power consumption is caused by the toggling of long signal buses.
For this and other reasons, there is a need for the present invention.